Experimental and PM6/SPARKLE Semiempirical Study of Interaction between 4-Methoxyphenylcyanamide and Gadolinium(III) as a Fast Polymeric Membrane Sensor



In this study, a highly sensitive PVC–membrane sensor based on 4-methoxyphenylcyanamide (4-MeOpcyd) as a neutral carrier was prepared and the specific interaction between Gd3+ ions and ionophore at the surface of selective polymeric membrane was calculated using the PM6/SPARKLE semiempirical method. The results of the Mopac2009 calculations show selective complexation of Gd3+ by 4-MeOpcyd ligand that correlate quite well with experimental data. This membrane sensor has a linear response in the range of 1.0×10−6–1.0×10−2 M Gd3+ with detection limit of 6.2×10−7 M. This electrode was applied in potentiometric titration for determination of gadolinium and also for fluoride ions in the mouthwash samples with satisfactory results.